Sensor characterization is the process of understanding the functionality of the sensor. Sensor characterization includes, but is not limited to, performance metrics such as conversion gain, dynamic range, read noise, dark current, saturation capacity, uniformity, defect pixels, quantum efficiency, modulation transfer function, and timing accuracy. The characterization of electronic image sensors begins with characterizing the photon transfer of a light signal input to an electrical signal output. The traditional photon transfer method compares a camera's output signal and noise across all pixels collectively to determine a conversion gain constant that relates digital grey values to electrons. The method known as photon transfer was developed initially for the characterization of video tube image sensors. The photon transfer method was subsequently applied to a variety of image sensors for the characterization of the transfer of photon signal to digital number output. It was subsequently discovered through both experimentation and theoretical analysis that the underlying assumptions of the traditional photon transfer method rendered the method insufficient for many modern sensors, and that the data products of the traditional photon transfer method lacked detailed information useful for whole sensor characterization.